TGFB1 and Hyperglycemia: It's been established that the condition of hyperglycemia results in a fourfold increase in the Sp1 transcription factor's O-GlcNAcylation; in TGF-b1 cells of the vascular smooth-muscle and PAI-1 within endothelial cells of the arterial wall, it is responsible for the induction of hyperglycemia, which then triggers the PAI-1 promoter..48